A triangle has corners at (8,5), ( 2, -7),and( 1, -2 )#. If the triangle is reflected across the x-axis, what will its new centroid be?
1 Answer
May 18, 2018
Explanation:
begin by calculating the coordinates of the centroid
given the coordinates of the vertices of a triangle say
(x1,y1),(x2,y2) and (x3,y3)
then the centroid is the average of the x and y
coordinates of the vertices
centroid =[13(x1+x2+x3),13(y1+y2+y3)]
⇒[13(8+2+1),13(5−7−2)]=(113,−43)
under a reflection in the x-axis
∙ a point (x,y)→(x,−y)
⇒(113,−43)→(113,43)←new centroid